This project investigates the emotional deficits that can give rise to extreme behavioral disturbance; high levels of instrumental antisocial behavior coupled with an absence of expressed guilt/ remorse. Currently, there are two main positions regarding the neural systems that are dysfunctional in such individuals: First, that the pathology is associated with amygdala dysfunction; Secondly, that the pathology is associated with orbital frontal cortex dysfunction. Identification of the neuro-biological underpinnings of their emotional dysfunction is of crucial importance as the level of emotion dysfunction is an important predictor of long term prognosis. The current project determines the performance of individuals with extreme behavioral disturbance and comparison individuals on measures which recruit the amygdala and orbital frontal cortex. In addition, a series of functional neuro-imaging studies will directly assess neural responses in these two systems in these individuals. Finally, a structural imaging study will examine anatomical differences between the groups. The project should provide clear data that will constrain future theorizing on the pathology implicated in this disorder.